Beer Forum

I had my 5# CO2 tank filled on Monday, and Tuesday afternoon it completely emptied itself (in about a minute or so). I wasn't home at the time, I just got a call from my frightened wife. It wasn't hooked up to a regulator or anything, just sitting around waiting for me to hook it up, and it just started venting somehow.

Is there a relief valve that broke or anything? Should I have it tested? I can't see any parts that are actually broken.

Ideas? Thanks.

I hear the PRV has a small disk in it. When it blows, you have to replace the disk (or maybe the assembly). My LHBS guy said it's about $10.


Mylo

Any guess where I could get a new one? (I don't have a LHBS and I couldn't find anything on morebeer or NB...then again I'm also an idiot so I may just not be looking for the right thing)

SphericalCamel wrote:Any guess where I could get a new one? (I don't have a LHBS and I couldn't find anything on morebeer or NB...then again I'm also an idiot so I may just not be looking for the right thing)

Check with the place you get your tank filled. If they can't fix it, they should be able to direct you to someplace that can.

Wayne

thanks! will do.

If the regulator wasn't on the tank then it was the rupture disk (on the opposite side of the tank thread-in under the cap with the little holes drilled in it). When these go it is quite spectacular and your wife was thoroughly justified in being frightened or at least startled. Did she describe loud noise, the bottle falling over and rolling around or it becoming sheathed in ice? These are things that usually happen when a rupture disk goes and it only takes a few seconds to empty the tank.

The only things that will cause them to blow are heating way above the critical temperature (the pressure gets high enough to pop it and that's exactly what it's for) or it was overfilled with cold CO2 in which case the liquid expands as it warms and the pressure shoots up as the (too small) headspace gets compressed. Again, that's what the disk is there for.

In either case the pressure in the tank went too high and I believe DOT regulations require that it be hydro tested before it can be refilled. As your supplier refilled it he should bear the cost of this.

But it's a little hard to imagine that the supplier overfilled. It takes some effort to accomplish this (yes, I know how to do it and have done it) and the supplier is usually more motivated to underfill somewhat so I suppose it is possible that the rupture disk was defective.

In any case, the disk will need to be replaced. If you supplier is a welding supply shop or general gas supplier and the bottle is theirs they should do this for you. If it is your bottle they may be reluctant to sell you the part (because of liability concerns) but will probably service it for you i.e. put in a new disk and do a new hydro test. Who pays for this may be the subject of discussion. If you can convince them they overfilled it, then you will probably be accomodated. If they won't accept that and blame the disk itself you are probably stuck.